Systems and structure for controlling the movement of well pipe in well bores



Oct. 25, 1955 D. M. SIMMONS SYSTEMS AND STRUCTURE FOR CONTROLLING THE MOVEMENT OF WELL PIPE IN WELL BORES Filed April 17, 1952 Drur 4 Sheets-Sheet 1 M 3/07/77 on:

INVENTOR.

Get. 25., 1955 SIMMONS D. M. SYSTEMS AND STRUCTURE FOR CONTROLLING THE MOVEMENT 0F WELL PIPE IN WELL BORES Flled Aprll 17, 1952 4 Sheets-Sheet 2 Drury M J/mm ons INVENTOR.

ATTORNfYJ Oct. 25, 1955 D. M. SIMMONS SYSTEMS AND STRUCTURE FOR CONTROLLING THE MOVEMENT 0F WELL PIPE IN WELL BORES 4 Sheets-Sheet 5 Filed April 17, 1952 8 0 w m M; H d i|\\\l!| 7 u v 5 m M m 4 2 m 2 5 J a, A l: v M M K a "M m f u/ l c k w a W x 9; m w II M Q /n d h U |rE 0 A i WW W .I/ W7 M #6 1 7 6 m w 4 C 5M u fvwn h j w z 2., A w W 7 m" \\\\l-w\1 aflv mflmy 7 14;"! M 1 ll"" I h glf q T Il L H u 7 7 67 H 4 J 9% 4251: a a a Z 90 Z c @3 5 w m u Oct 1955 D. M. SIMMONS SYSTEMS AND STRUCTURE FOR CONTROLLING THE MOVEMENT OF WELL PIPE IN WELL BORES 4 Sheets-Sheet 4 Filed April 17, 1952 Dru/y M J/mmons INVENTOR.

BY 21 W zzwbL ATTORNEYS United States Patent SYSTEMS AND STRUCTURE FOR CONTROLLING THE MOVEMENT OF WELL PIPE IN WELL BORES Drury M. Simmons, Shreveport, La.

Application April 17, 1952, Serial No. 282,859

19 Claims. (Cl. 166-46) This invention relates to new and useful improvements in systems and structures for controlling the movement of well pipe in well bores.

It is an increasingly common occurrence in the petroleum industry to encounter wells in which considerable pressure exists. The pressure may be present either in a completed well which is producing petroleum, or in a well which is being drilled or deepened; the pressure in the latter case usually being due to a gas sand or formation through which the well bore has passed. In either instance, the pressure may amount to several thousand pounds per square inch and present serious problems to the operator. It is sometimes necessary to clean out or otherwise service a producing well, and such operation often involves pulling the tubing or other pipe from the well bore and subsequently running the tubing back in the well. It is in the latter operation that most difficulties are encountered since the pressure in some wells is sufiicient to prevent the tubing being introduced or lowered into the well through the force of gravity alone.

However, the pulling of the tubing maybe equally difficult, since the pressure is sometimes sufiicient to overcome the weight of the tubing string and force it upwardly in the well bore, in which case control of the tubing or other pipe is .lost.

Due to the well pressure occurring under the above conditions, it has beenv common practice to lower well tubing into wells wherein considerable pressure exists by the use of the well known snubbing equipment. Such snubbing equipment generally includes a set of stationarypipe gripping slips and a set of movable slips, both of which are actuated through wire lines and other complicated equipment therewith for operation in the known manner. Such snubber equipment has numerous disadvantages or undesirable features such as the fact that the wire lines must be depended upon to 'hold the pipe without the use of the usual snubbing equipment.

An important object of this invention is to provide an improved system and structure for controlling the movement of well pipe in a well borewherein such movement can be efiected with the packing elements of the blowout preventer retracted.

A further object of this invention is to provide an improved system and structure for controlling the lowering and raising of well pipe in a well bore in which a cylinder assembly is utilized for such'control, and wherein said cylinder assembly is power actuated to facilitate handling of the assembly and the well pipe connected therewith.

A still further object is to provide in a system and structure for controlling the movement of well pipe in a well bore, a cylinder assembly having a dual piston arrangement, whereby a high degree of control of the pipe is maintained during lifting thereof from the well bore.

A construction designed to carry out the invention will be hereinafter described together with other features of the invention.

The invention will be more readily understood from a reading of'the following specification and by reference to the accompanying drawings, wherein an example of the invention is shown, and wherein:

Fig. l is a side elevation of one embodiment of the invention, showing schematically the necessary elements of the system as applied to the manipulation of a tubing string in a well bore,

Fig. 2 is an enlarged, vertical, sectional View of the structure shown in Fig. l of the drawings,

Fig. 3 is an enlarged, side elevation of the structure shown in Fig. 1,

Fig. 4 is a view similar to Fig. l and showing a modification of the system as applied to the feeding of drill pipe into a well with provision being made for rotating the pipe,

Fig. 5 is an enlarged, vertical, sectional view of the upper portion of the structure shown in Fig. 4 and,

vertical, sectional view of the lower portion of the structure shown in Fig. 4.

Fig. 7 is a vertical sectional view of the upper portion of a modified control structure wherein a dual piston arrangement is utilized, and illustrating the lower piston in its extreme raised position in the cylinder.

Fig. 8 is a view similar to Fig. 7, illustrating the lower piston in its extreme lowered position.

In the drawings, the numeral 10 designates the usual easing which is set in the well bore and serves to enclose or wall in the same, so that any gas pressure present in the well is exerted within the casing, and closing off or sealing of the latter will prevent the escape of gas under pressure. Connected above the casing 10 is a master valve 11, a blow-out preventer and power actuated slips 42. Snubbing equipment is normally located above such apparatus for feeding pipe into the casing when the well pressure is such that the pipe cannot be lowered into the casing by the gravitational force of its own weight. In this invention, instead of such snubbing equipment, a cylinder assembly C is located above the slips 42, blow-out preventer 3%, and master valve 11, and has connection therewith through a quick-release coupling 70. This cylinder assembly C is attached to a hook 83 on the conventional travelling block 82 of a well derrick (not shown) so that the cylinder assembly C may be moved away from or toward the rest of the apparatus therebelow when the coupling is disengaged. The cylinder assembly C, when the coupling 70 is engaged, is adapted to control the raising and lowering of tubing or pipe P into or from the casing 10 by hydraulic or gas means, such operation to be described in detail hereinafter.

The first form of the invention to be described is shown in Figs. 1 through 3 .of the drawings, and is adapted for use under various conditions wherein it is necessary to run pipe or tubing into or out of the well under pressure, such as in cleaning out or otherwise servicing a producing well or in drilling a well which has not as yet been completed. For the purposes of illustration, the system and structure-will be described in connection with the introduction or removal of a string of pipe into or from the well bore. However, it is to be kept in mind that other and varied uses of the invention may be made.

The master valve 11 is secured to the upper end of the casing 10. This valve is provided for the purposes of shutting off the entire bore or cross-sectional area of the casing and includes a cylindrical housing 11' having a valve element or cone in the form of a piston 12 mounted transversely therein so as to reciprocate diametrically of the axial bore or flow passage 13 of the housing. The flow passage 13 extends vertically through the housing of the valve in axial alinement with the bore of the casing 10. Annular, laterally-directed flanges 15 and 16 are provided on the lower and upper faces respectively, of the housing, said flanges encircling the lower and upper ends, respectively, of the flow passage 13. The flanges provide for securing of the valve body to the casing and to elements above the valve, the casing carrying a flanged collar 17 at its upper end for this purpose. Suitable bolts 18 extend through the flange of the collar 17 and the lower flange 15 of the valve housing or body to secure the valve in position in vertical alinement with the casing.

The valve core or piston 12 is carried within a laterallyextending branch 19 of the housing 11', said branch being formed integrally with the housing. The branch is provided with a cylindrical bore 20 within which the piston 12 has a snug sliding fit, said bore projecting at right angles from the flow passage 13. The bore is greater in diameter than the flow passage and extends diametrically thereacross so as to form guides 21, arcuate in cross-section, in the side wall of said passage. The side wall of the housing 11 opposite the branch 19 is dished or internally concave, and carries a seat 22 in the form of a horizontal rib extending transversely of the passage 13 and diametrically of the bore 20. A resilient seating element 23 is countersunk in the end of the piston 12 and adapted to engage the rib 22 for sealing off the flow passage. Thus, an effective means for closing off the flow passage is provided.

In its retracted position, the valve core is disposed wholly within the branch 19 so that the flow passage 13 is unobstructed and tubing or oil well tools may be readily passed therethrough.

For reciprocating the valve core 12, a cylinder 24 is secured to the outer end of the branch 19 and carries a hydraulic piston 25 within its bore 26. The piston 25 is connected to the valve core by means of a piston rod 27 and suitable inlet and outlet pipes 28 extend through the side walls of the cylinder 24 for admitting and releasing hydraulic fluid to cause the piston 25 to move laterally within the cylinder and thus move the valve core into a closed or extended position or into an open or retracted position. Any suitable or desirable means such as a source of hydraulic fluid under pressure (not shown), may be provided along with suitable control means (not shown) for actuating the valve 11.

The sealing unit 30 serving as a blowout preventer is disposed above the master valve 11 and includes a housing 31 of substantially cruciform shape. This sealing unit or blow-out preventer 30 is of a well-known construction having a vertical flow passage 32 extending through two diametrically-opposed branches of the housing 31, and a pair of horizontally disposed rams 33 carried Within the two diametrically-opposed branches. The rams 33 are adapted to be reciprocated within the housing by means of pistons 34 connected thereto by suitable piston rods 35. The pistons 34 are operable within hydraulic cylinders 36 secured upon the outer ends of the latter two branches of the housing. Suitable inlet and outlet pipes 37 admit hydraulic fluid under pressure on either side of the pistons 34 to cause the rams 33 to move inwardly toward the center of the flow passage 32 or to move outwardly to a retracted position wherein the flow passage is substantially unobstructed. The vertical branches of the housing 31 carry annular flanges 38 about their outer ends, the lower flange 38 being secured to the flange 16 of the valve 11 by means of suitable bolts 39. The flow passage 32 is thus secured in axial alinement with the passage 13 and the bore of the casing 10.

The rams 33 carry arcuate, resilient inserts or packing elements 40 on their inner, arcuate, abutting faces 41. Thus, when a length of pipe or tubing is positioned within the passage 32, the rams may be moved inwardly by means of the hydraulic pistons 34 so as to engage the tubing between the inserts or packing elements 40 and pack off the space around the exterior of the tubing, whereby communication between the upper and lower end of the passage 32 exterior of the tubing is shut off.

The sealing unit is very similar in structure and function to the normal and usual blow-out preventer and further description of the sealing unit is not deemed necessary. The function of the unit in the present instance is to retain pressure within the casing 10 when a length of tubing is extending downwardly therein, even though the upper portion of the passage 32 may be open to the atmosphere.

The pipe gripping unit or slips 42 is provided above the sealing unit 30, the unit 42 being similar in nearly every respect to the unit 30 with the exception of the rams 33 of the latter. In the tubing anchoring or gripping unit 42, the normal type of ram is replaced by a pair of rams 43 similar in shape to the rams 33 but having arcuate gripping teeth 44, of the nature of wickers, cut into their outer, arcuate, pipe-engaging faces. As is clearly shown in Fig. 2 of the drawings, the teeth 44 are divided into an upper and a lower section, those teeth in the upper section being directed upwardly while the teeth in the lower section are directed downwardly. Thus, when a pipe is engaged between the pipe gripping faces of the rams 43, the former is held against both upward and downward movements.

A pair of cylinders 46, similar to the cylinders 36, carry pistons 47, similar to the pistons 34, and are adapted to receive hydraulic fluid under pressure through inlet and outlet pipes 48 for moving or forcing the rams 43 into an extended or a retracted position. In this manner, the rams may be actuated by means of a hydraulic fluid to grip or to release the pipe or tubing extending through the vertical flow passage of the gripping unit. Any suitable or desirable source of hydraulic fluid (not shown) may be utilized to provide hydraulic fluid under pressure for the sealing unit 30 and the pipe gripping unit 42. In addition, suitable control means or elements (not shown) are preferably connected into the inlet and outlet pipes 37 and 48 to control the operation of these two units. Obviously, a separate control means may be utilized for each of the units so that they may be operated either separately or together. However, if desired, both units may be controlled by a single valve or other element so that the two units operate in unison.

The sealing unit and the pipe-griping unit being in axial alinement with the casing 10, may be considered as continuations of the latter, and the entirety termed a conductor. Of course, it is immaterial which of the units is placed above the other, or whether they conform to the exact structure described. It is the function rather than the specific mechanical embodiment of these units which is of importance.

For the purpose of equalizing gas pressures above and below the units 30 and 42, a suitable pipe or conductor 49 is connected into the lower portion of the fluid passage 32 of the lower unit 30, such connection being made at the point 50 below the rams 33. The pipe 49 extends laterally from the unit and is connected into an upwardlyextending pipe 51 having therein a suitable shut-off valve 52. The upper end of the pipe 51 connects into a T 53 which has one lateral branch connected by a suitable pipe 54 to the upper end of the flow passage of the pipe gripping unit 42, such connection being made at the point 55 above the rarns 43. The other branch of the T 53 has connected thereto a suitable pipe 56 carrying a shutoff Valve 57, If desired, a similar valve 58 may be connected into the pipe 54 between the T 53 and its point of connection to the flow passage of the unit 42. Other and additional functions of this piping connection will be set forth more fully hereinafter.

The cruciform housing or body 45 of the unit 42 is, of course, similar to the housing 31 of the unit 30, and is provided with an upwardlyextending and a downwardlyextending leg through which a flow passage 59 extends. The lower branch carries a suitable annular flange 60 en' circling the lower end of the passage and adapted to abut the flange 38 of the unit 30. The two flanges are secured together by means of suitable bolts 61 so that the flow passage 59 of the unit 42 is placed in vertical alinement with the flow passage 32 of the unit 30. A similar annular flange 62 surrounds the upper end of the flow passage of the unit 42 and receives the annular flange 63 of a collar 64 positioned above the unit 42. The flanges 62 and 63 are secured together by means of suitable bolts 65 so that the collar 64 is anchored in a position wherein its axial passage 66 is in vertical alinement with the flow passage 42. Obviously, all of the various flanged connections recited may be replaced or eliminated by the use of welded joints or by any other suitable connecting means. The flanged joints are shown merely for the purposes of illustration.

The quick-acting union or coupling 70, of usual construction, is provided at the upper end of the collar 64. For this purpose, the collar 64 carries at its upper end external screw-threads 67 of a relatively coarse nature and normally of the style known as Acme. The cylinder assembly C, including an elongate pressure cylinder or chamber 68 is positioned above the collar 64 and in vertical alinement therewith, the internal diameter of the cylinder 68 being substantially the same as, and the external or outside diameter of the cylinder 68 being slightly less than, that of the collar 64. The cylinder 68 carries an external, annular flange 69 upon its lower end, said flange being adapted to rest upon the upper end of the collar 64. The quick-acting coupling or union 70 encloses the joint between the cylinder 68 and the collar 64. The coupling carries internal, relatively coarse screwthreads 71, similar to the threads 67 and adapted to engage therewith. An internal annular flange 72 is provided in the upper portion of the coupling 70, such flange being adapted to overlie and engage the flange 69 and prevent upward movement of the cylinder 68 with respect to the collar 64. The coupling 70 is of the split-half type in which two semi-circular halves are joined at one side or end by a transverse pin or bolt 73 and carry laterally-extending ears 74 at their opposite side, said ears being urged together by means of a bolt 75 extending through the same. The coupling may thus be quickly released by loosening of the bolt 75 so as to permit the halves of the coupling to swing apart and release their engagement upon the threads 67. Similarly, the coupling 70 may be tightened by rotation thereof and tightening of the bolt 75 so as to provide a snug and secure joint between the flange 72 of the cylinder 68 and the flange 69 of the collar 64. If desired, suitable packing means (not shown) may be disposed between the upper and lower ends of the collar and cylinder respectively, so as further to enhance the fluid tightness of this joint.

The length of the cylinder 68 is dependent upon the utilization of this system and structure. In the present example wherein only the introduction of single lengths of pipe or tubing into the well bore is contemplated, the cylinder may be from to feet in length, this figure being based on the assumption that the ordinary length of pipe is 27 feet in length. However, longer or shorter cylinders may be utilized in accordance with the particular requirements at hand.

A piston element 76 has a snug sliding fit within the bore 77 of the cylinder 68 and is provided with an elongate guide rod or tube 78 extending vertically upward therefrom. The rod 78 may be formed integrally with 6 the piston 76 or secured thereto in some suitable fashion. The rod projects through the upper end wall 79 of the cylinder 68 through a suitable packing gland 80, and

carries an eye 81 in its extreme upper end. The overall length of the rod 78 is such as to permit the piston 76 to move to the extreme lower end of the cylinder while the eye 81 remains positioned above the packing gland 88, and an internal flange or rib 68' may be provided to limit such downward movement. Obviously, when the piston 76 is at the upper end of the cylinder, a considerable length of the rod 78 will be exposed above the packing gland 8G. The usual travelling block 82 of the normal oil well drilling rig has its hook 83 engaged withinthe eye 81.

A pressure fluid conductor 84 connects into the upper end of the cylinder 68 and is preferably joined to a flexible hose 85 which extends upwardly from the derrick floor A and has connection with. a control or shut-off valve 87 at a suitable operating position or level, the latter normally being adjacent the derrick floor.

A suitable swivel 88 is carried by the piston 76 and depends from the lower side thereof within the cylinder 68. A screw-threaded pin 89, or other connecting means, is provided upon the lower end of the swivel 88 so that a length of tubing or pipe P may be secured thereto through a coupling sleeve 86.

In the operation of the structure shown in Figs. 1-3, before any tubing or pipe P has been lowered into the casing 10, the master valve 11 is closed to seal off the well therebelow. The blow-out preventer 30 and the slips 42 may be in their inner position, as shown in Fig. 2, or they may be retracted, if desired, since the master valve 11 is closed. With the piston 76 in its upper position (Fig. 2) with a section of tubing or pipe P connected therewith, the cylinder 68 is connected to the collar 64' by the coupling 70. After such coupling is made up, the valves 52 and 58 are closed, the master valve 11 is opened and the blow-out preventer 38 and slips 42 are moved to their retracted or open position, thus exposing the cylinder 68 to the full pressure of the well. if the well pressure is so great that the pipe P cannot be lowered on the block 82 by reason of its own weight, it is forced downwardly by a gaseous or hydraulic fluid admitted above the piston 76 by opening of the valve 87. The travelling block 82 and hook 83 attached to the eye 81 are permitted to lower with the pipe P. When the piston 76 reaches its lowermost position, which is slightly above the lower end of the cylinder 68, the blow-out preventer 30 and the slips 42 are actuated to an inner position by a gaseous fluid through their lines 37 and 48, respectively, so that they contact and surround the outer surface of the pipe P, with the slips jaws 44 holding the pipe and the packing elements 40 sealing off the annular space between the pipe P and the housing 31. The valves 57 and 58 may then be opened to the atmosphere, whereby the pressure below the packing elements 40 is that of the well whereas the pressure thereabove is that of the atmosphere. It should be noted at this point that there was no 'contact of the resilient packing elements 46 with the pipe P until such pipe P had stopped its downward travel, so that there is no rubbing wear on the packing elements 48 as usually occurs when using conventional snubbing equipment for lowering well pipe through a blow-out preventer. It will be appreciated that the first section of pipe P inserted in the casing 10 will have the usual back pressure valve at its lower end to prevent well fluid from passing upwardly through the pipe P.

After the pressure in the space above the blow-out preventer 30 is atmospheric, the coupling 70 is released and the cylinder 68 of the cylinder assembly C is raised sufficiently by the admission of more fluid under pressure from the line to expose the collar 86 connected to the threaded pin 89 of the piston 76. The threaded pin 89 may then be disconnected from the collar 86 and pipe P by rotation thereof with conventional tongs (not shown). During such rotation, the swivel 88 may rotate to prevent rotation of the piston 76. When the pipe P has thus been disconnected, it is held in the apparatus by the slips 42 and the cylinder assembly C is free to be moved away from the apparatus therebelow by means of the travelling block 82 to pick up the next section of pipe P. With the piston 76 in its lowermost position, this next section of pipe P is connected to the pin 89. Then the pressure above the cylinder is partially released so that the piston 76 moves upwardly, retracting the pipe P connected thereto so that only the lower portion of the pipe is exposed below the cylinder 68. The cylinder assembly C is then swung over the apparatus and the section of pipe P connected to the piston 76 is threaded into the section of pipe P previously placed in the casing. After the threaded joint between the sections of pipe is made up, the rest of the pressure above the piston 76 is released so that the cylinder 68 is lowered into contact with the collar 64. The coupling 70 is then secured, the valve 58 closed, and the slips 42 and unit 30 are released, again exposing the cylinder 68 to the full well pressure. The pipe P is lowered in the same series of steps previously described.

In pulling the tubing or pipe P out of the well, the steps are substantially the reverse of running in the pipe. With the cylinder 68 connected to the collar 64 and the piston 76 in its lower position, the slips 42 and blow-out preventer 30 in their closed position, and the valve 557 closed, the valves 52 and 58 are gradually opened to bleed the well pressure from below the unit 30 through the opening 51) and then through the opening 55 to equalize the pressure above and below the unit 30. The preventer 30 and slips 42 are then opened whereby the piston 76 is forced upwardly by the well pressure, by regulating the discharge of the pressure above the piston '76 by controlling the extent of the opening of the valve 87. When the piston 76 reaches its upper position, the slips 42 are set and the blow-out preventer 30 is sealed around the pipe P. If the last section of pipe had been pulled, the master valve 11 would also be closed. Valves 57 and 53 are opened, and if the master valve 11 is closed, then valve 52 would also be opened, so that the well pressure is confined below the preventer 30 or the master valve 11 with the pressure thereabove being atmospheric. The coupling 70 is then released and the cylinder raised relative to the piston 76 by admitting pressure from line 85. If a section of pipe P still remains in the casing 10, then the joint between such section and the pipe section in the cylinder 68 is disconnected so that the cylinder assembly C can be moved to one side of the apparatus therebelow. The piston 76 can then be moved to its lower position for disconnection of the pipe P therefrom. After such disconnection, the cylinder 68 can be returned to its position above the well bore and can then be connected to the upper section of pipe still in the casing 11). After the cylinder 68 is coupled to the collar 64, the same series of pulling out steps are repeated until all of the pipe P is pulled.

A modified form of the invention is illustrated in Figs. 4, and 6 of the drawings. This modification makes provision for rotation of the tubing or pipe while it is being moved downwardly in the well bore under pressure. Obviously, this latter function is necessary under such circumstances as encountered in drilling under pressure. There are other applications such as certain types of fishing operations wherein it is necessary to cut or to hook a ruptured section of pipe or tubing which may be lodged within the well bore. Rotative as well as longitudinal movement of the string of pipe is often necessary in such instances. Other varied and obvious uses are readily apparent.

The structure of Figs. 46 is substantially the same as the apparatus of Figs. l-3 with the exception that a rotary mechanism 100 for imparting rotation to the string of pipe P, and means for supplying drilling mud to the well bore '8 are provided in this second form of the invention. As in Figures l-3, the master valve 11, blow-out preventer 30 and slips 42 are mounted above the casing 10 (see Fig. 6). Instead of the cylinder assembly C being connectable above the slips 42 as in Figs. l-3, there is mounted above such slips 42 the rotary mechanism 100.

The rotary mechanism 180 includes a substantially cylindrical housing 101 having a flange 102 at its lower end for connection to the flange 62 of the slips 42 with bolts 65. The housing 101 is thus a continuation of the housing 45 of the slips 42.

The housing 101 is enlarged in diameter both internally and externally at a point spaced above the lower end thereof, and an internal annular flange or rib 166 is provided at such points of enlargement. An internal annular shoulder 107 is formed immediately above the flange 106 and receives a suitable anti-friction bearing 183. The latter may be of the roller or ball bearing type or of other suitable or desirable nature. A similar bearing M9 is positioned in the upper portion of the housing 191 and rests upon a narrow, internal, annular, upwardly-directed shoulder 110 formed by enlarging the internal diameter of the housing from this point upward. The housing carries internal screw-threads 111 for a short distance above the shoulder 110, and an externally screw-threaded circular ring 112 engages said screw-threads 111. Thus, the ring 112 may be screwed downwardly into snug engagement with the upper side of the bearing 10) so as to clamp the latter in position between said ring and the shoulder 110 and prevent upward movement of the hearing.

The bearings 108 and 109 are preferably of the inclined race type so as to withstand both lateral or radial as well as endwise or thrust stresses or loads. The bearings serve as a mounting for a rotary element 113 disposed within the housing 101. The element 113 has an elongate cylindrical body provided with an axial passage or bore 114 and a reduced depending shank 115. Near its central portion, the element carries an external annular flange 116 having inclined gear teeth out in its upper side to form a bevelled gear 117. The underside of the flange 116 engages the upper side of the bearing 108 so as to support the element 113 within the housing 101 and prevent its downward movement thereto. A similar flange 118 is formed on the element 113 and positioned a short distance above the flange 116 so as to have its upper side engaging the lower side of the bearing 109. Thus, upward movement of the element 103 is prevented by the bearing 109 and the ring 112. By reason of their inclined race structure, the bearings 108 and 109 carry the endwise thrust load exerted by the element 113 as well as provide an anti-friction mounting for said element.

The reduced shank extends downwardly through the circular opening 119 defined by the annular flange or rib 106, the inner periphery of said flange having a snug sliding fit with the outside wall of said shank. The rib 106 carries a peripheral recess 120 in its inner and lower face, and suitable oil rings 121 are disposed in said recess so as to have snug engagement with the outer wall of the shank 115. In this manner, a body of lubricants (not shown) may be carried within the upper portion of the housing 101 and its leakage or dissipation downwardly between the flange 106 and the shank 115 prevented. Obviously, the lubricant serves the bearings 1G8 and 109 as wfell as the driving gear connection to be described hereina ter.

A tapered screw-threaded pin 122 is provided upon the upper end of the element 113 above the shoulder or flange 118 and engages within a screw-threaded box 123 formed on the lower end of a circular bowl section 124. The section 124 is enlarged in outside diameter above the box 123 so as to be only slightly less in diameter than the upper portion of the housing 101. The usual type of slip bowl 125 is formed in the upper portion of the element 124 and has the usual inclined side walls common in such bowls. A pair of tapered slips 126 are adapted to fit within the bowl 125 and engage: the square stem of anordinary Kelly joint or kelly 127. As. is usual in such structures, the kelly 127 is prevented by the slips 126 from rotating with respect to the elements 124. and 113, but is free to move or slide. upwardly and downwardly through the slips and the bore 1.1.4.

For rotating the element 113, a beveled pinion 128 is carried upon a shaft 129 suitably supported upon bearings in a cylindrical sleeve 1'30 projecting laterally of the housing 101. The pinion 128 is so positioned as to mesh with the gear 117 so that rotation of the shaft 129 results in rotation of the elements 113 along with the bowl 124. The slips 126 serve to transmit this rotative force from the bowl unit 124 to the kelly 127 whereby the latter may be rotated as it moves upwardly or downwardly through the slips and the passage 114.

External screw threads 131, similar to the threads 67 on collar 64 previously described in connection with Fig. 2, are provided upon the upper end of the housing 101. The coupling 70 connects the cylinder 68 of the cylinder assembly C to the threads 131. The cylinder assembly C is substantially identical to that shown in Figs. 1-3, except that shank 178 differs from shank 78 in that shank 178 is hollow and has an axial passage 178 therethrough which communicates with a flexible mud line 186. The kelly 127 is connected to the pin 189 by a collar 127a, whereby mud or drilling fluid may be admitted from line 186 and pass downwardly to the bore 127" of the kelly 127 through the passage 178". It will be appreciated that the lower. end of the kelly 127 is provided with a threaded connection to the usual drill pipe P therebelow so that the mud can be conducted to the drilling bit connected to the bottom of the drill pipe.

The operation of the apparatus' of Figs. 4-6 is the same as that of Figs. 1-3 insofar as the insertion and removal of the well pip'e P is concerned. During such insertion and removal of the pipe P, the tapered slips 126 are removed from the bowl 125. to allow sufiicient space for the pipe P to pass through the mechanism 100.

With the pipe P supported in the well bore by slips 42 and the upper end of such pipe extending above the bowl 125, the lower end of the kelly 127 is connected thereto in the same manner as a section of pipe. The cylinder 68 is then lowered and connected. to the threads 131 by the coupling 70. The valves 52 and 58 are closed and the slips 42 and preventer 30 are opened. Pressure is applied to the piston 76 to. move the kelly downwardly until the. lower portion of the kelly 127 is within the bowl 125'. At this point the drilling bit will normally be resting on the bottom of the well bore. The slips 42 and preventer 30 are then closed and the valve. 97 is opened to the atmosphere. The coupling 70 is broken so. that the cylinder: 68 can be raised to permit the introduction of the tapered slips 126 for locking the kelly 127 rotatively to the bowl 124 and body 113. After the coupling 70 is made up again, the valve 58 is closed and slips 42' and preventer 30' areretracted'. Rotation of the kelly is then obtained by driving. the pinion 128 by suitable means (not shown.) which in turn drives the bowl 124, through the gear teeth 1.17. A downward force may be applied to the. drill string by admitting fluid under pressure above the piston 76.

When the drilling bit has moved downwardly to such an. extent as to bring the upper end or portion of the kelly into engagement with the slips 126, the pressure within the cylinder 68' is reduced so as. to allow the piston. 76 to move upwardly and thus raise the drilling string. This raising action is continued until the lower end" of the kelly has moved to a point immediately above the bowl unit 124. In so moving, the lower end of the kelly and the upper end of the first string or length of drill pipe will force the slips. upwardly out of the bowl 125' so as to disengage rotatively the kelly from the rotary unit. When the elements are in this position, the sealing unit 92 and the pipe gripping unit 93 may be actuated or closed to seal off the casing below the sealing unit and to anchor the drilling string in posit-ion within the well bore. The pressure within the upper part of the system may then be exhausted and the joint between the cylinder and the rotary unit broken so as to allow disengagement of the kelly from the upper end of the first length of drill pipe. An additional length of drill pipe is then connected onto the lower end of the kelly and both elements drawn upwardly into the cylinder 68 by suitable movement of the piston 76. The lower end of this additional string of pipe is then connected into the upper end of the upper length of pipe within the well bore, said upper end being disposed immediately above the unit 124. Upon completion of the making of these joints, the cylinder 63 is lowered and connected to the rotary unit by the collar 70. Then, pressure may be equalized between the upper and lower sides of the piston 134 and the sealing unit, and the pipe engaging unit 42 opened so as to allow the pipe to be moved downwardly in the well bore until the drilling bit reaches the bottom of the well bore. Because the kelly is greater in length than the standard length of drill pipe, the lower end of the kelly will be positioned within the bore when the drilling bit reaches this position. However, the upper end of the added length of drill pipe will be in position between the top of the unit 42 and the sealing unit 30. The latter units may be closed so as to seal off and grip the pipe and the pressure again exhausted from the cylinder 68. The coupling 70 is then released and the cylinder moved upwardly from the rotary unit to allow the introduction into the bowl 125 of the slips 126. After again connecting the cylinder to the rotary unit, the drilling operation may proceed.

This operation follows very closely normal rotary drilling operations, the major differences residing in the necessity for shutting off or sealing in the pressure present within the casing 10 and for manipulating the sealing unit and the various valves in order to keep such pressure under control while making, connections or disconnections, or while introducing or removing the slips 126 in the course of drilling operations. Obviously, many other types of operations may readily be carried out under severe pressure conditions by suitable manipulations of the system herein set forth. The system constitutes in general an adequate provision for whatever operations may become necessary and allows the carrying out of such operations under severe pressure conditions.

in Figs. 7 and 8, the same structure as shown in Figs. 1-3 is utilized, except that a modified cylinder assembly C is substituted for the cylinder assembly C of Figs. 1-3. This modification permits greater control when pulling the well pipe P out of the well bore than with the cylinder assembly C.

In this form, the cylinder 268 is adapted to be connected to the collar 64 by the coupling 70 as in Figs; 13. The cylinder 268 is divided into an upper section 268a and a lower section 268b by a packing gland 280 mounted in a sleeve 290. The packing gland 280 has a central opening therein through which a shank 291 passes in sealing engagement therewith. On the ends of the shank 291 are a lower piston 276b and an upper piston 276a which. together constitute a dual piston. member 276; The lower piston 276b operates in the lower cylinder portion 268b and limits the upward movement of the dual piston member 276 by contact with ashoulder 292 on the lower end of the sleeve 290. Similarly the upper piston 276a travels in the upper cylinder portion 268a and limits the downward movement of the dual piston member 276 by contact with a shoulder 293 on the upper end of the sleeve 290. A weight 294 is connected to the dual piston member 276 by a flexible cable 295 which passes over a pulley 296 and through a tubular opening 297 in the cylinder 268. The position of the dual piston member 276 is indicated by the position of the weight 11 294 relative to a fixed scale 298 which may be graduated or marked as desired.

On the lower end of the dual piston member 276, below the piston 276b, there is located the same type of swivel 88 and threaded pin 89 as shown in Fig. 2. The lower cylinder portion 26812 is approximately the length of a normal section of pipe P (27 feet) so that when the dual piston member 276 is in its raised. to its extreme upper position, the pipe section may be within the cylinder 268 (Fig. 7). The upper cylinder portion 268a is somewhat longer than the lower cylinder portion 26817 in order to provide a space in which the auxiliary control piston 299 may operate. This piston 299 has a relatively short shank 278 which has an eye 281 at its upper end. The shank passes through the packing gland 280a. Movement of the piston 299 is controlled by the admission and release of fluid through the valve 87 and line 85 which are identical to such elements shown in Figs. l-3. Movement of the dual piston member 276 is effected by fluid under presure controlled by the valves 287, 287a, 2871) and 287c. When fluid under pressure is admitted through the valve 287, with the valves 287a and 2871: closed and valve 2871; open to exhaust, the piston member 276 moves downwardly. Conversely, when fluid under pressure is admitted through the valve 28711 with valves 287 and 287!) closed and valve 2870 open to exhaust, the piston member 276 moves upwardly. By regulating the extent of the opening of the exhaust valves 28'7b and 2870, the rate of movement of the dual piston member 276 may be controlled.

The operation of the apparatus of Figs. 7 and 8 is similar to the operation of the structure of Figs. 1-3, with the exception of the cylinder assembly C operation. Thus, before any pipe P is run into the well bore, the master valve 11 is closed and the blow-out preventer 30 and slips 42 may be open or closed as desired, since the well pressure is confined below the master valve 11. With the cylinder assembly C disconnected from the apparatus therebelow, it may be swung to the rathole where a section of pipe P is connected to the pin 89. This connection is made with the dual piston member 276 and the auxiliary control piston 299 in their lower positions. It will be appreciated that the shank 291 is of suflicient length to expose the pin 89 below the cylinder 268 (Fig. 8).

The dual cylinder member 276 is then raised to its upper position (Fig. 7) but the auxiliary piston 299 is retained in its lower position for swinging the cylinder assembly C over the collar 64. If a section of pipe P were already in the well bore with its upper end exposed above the collar 64, the lower end of the pipe section in the cylinder assembly C would be connected thereto by rotation thereof with tongs or similar means (not shown). Then the pressure above the piston 299 would be released to lower the cylinder 268 to permit it to be coupled to the collar 64 by the coupling 78. If no pipe is in the well bore, the cylinder 268 would simply be lowered and the coupling 70 made up without the need of connecting the two sections of pipe prior thereto. If no pipe is in the well bore, the master valve 11, preventer 30 and slips 42 would be opened. If pipe is already in the well bore, the master valve 11 would not be closed, of course, so it would only be necessary to open the preventer 30 and slips 42. In any event, at this point in the operation, the piston 276b would be exposed to the well pressure. The pipe P in the cylinder assembly C is lowered by applying fluid pressure through valve 287 to the space above the piston 276b with the valves 287a and 2870 closed and the valve 287!) open to the atmosphere. When the dual piston member 276 is slightly above its lower position, as indicated by the position of the weight 294 relative to the scale 298, the valve 287 is closed and downward movement of the piston member 276 is stopped. The slips 42 and preventer 30 moved to their inner or set position and the pressure thereabove is released by opening valves 57 and 58 as in Figs. l3. Thus, the pressure below the piston 276b is atmospheric and the well pressure is sealed below the preventer 30 so that the coupling can be disengaged. The cylinder 268 is raised to the position shown in Fig. 8 by admitting fluid under pressure above piston 299. Pin 89 can then be disconnected from the pipe P leaving the cylinder assembly C free to be moved to the rathole for picking up another section of pipe P and repeating the above series of steps.

One of the main advantages of the device of Figs. 7, 8 as compared to the device of Figs. 1-3 is in the control when pulling pipe out of the well bore. As was pointed out in the description of Figs. 1-3, the well pressure is utilized to raise the piston 76 and the rate of rise of such piston 76 is controlled by extent to which the valve 87 is opened. Such control of the valve 87 is often difficult and unless the elevator 82 is raised at the same rate as the piston 76, there is always the danger of the eye 81 becoming inadvertently disengaged from the hook 83. With the construction of Figs. 7, 8, there is no such danger since the dual piston member 276 is not connected to the eye 281 so that even if the piston member 276 moves to the upper position very rapidly, there would be no effect on the attachment of the eye 281 to the hook 83.

The pulling out of the well pipe P is substantially the reverse of the running in steps. With the slips 42 and the preventer 30 retracted and the pressure above the piston 276b reduced, the well pressure forces the piston 276b upwardly to the position shown in Fig. 7. If the well pressure is not sufficient, the pipe P may be raised by admitting fluid under pressure below the piston 276a. Then, the slips 42 and preventer 30 are closed to hold and seal off the pipe P. The pressure above the preventer 30 is released to the atmosphere, and then the coupling 70 is disengaged. After such disengagement, the cylinder 268 is raised so that the section of pipe P within the cylinder 268 may be disconnected from the pipe supported by the slips 42. The cylinder assembly C is then swung to the rathole where the section of pipe P is lowered by lowering the piston member 276 with pressure thereabove. After the pipe section has been disconnected from pin 89, the cylinder assembly C is returned to the collar 64 and the pin 89 is connected to the upper end of the pipe supported by the slips 42 (Fig. 8). When such connection is made, the cylinder 268 is lowered and the coupling 70 is connected, slips 42 and preventer 30 are released, and then the pipe P is raised and the upper section thereof removed in the same series of steps as above outlined.

It is believed evident from the drawings and the above description that a system and structure for controlling the movement of well pipe has been devised wherein the snubber equipment usually used for handling pipe in high pressure wells is eliminated.

The foregoing description of the invention is explanatory thereof and various changes in the size, shape and materials, as well as in the details of the illustrated construction may be made, within the scope of the appended claims, without departing from the spirit of the invention.

What is claimed is:

1. In a system for controlling the movement of well pipe in a well bore having a casing therein, the steps of, first enclosing a length of well pipe in a pressure tight chamber connected to the well casing, then admitting to the chamber the pressure fluid present within the easing, and controlling the pressure within the chamber to move the pipe longitudinally of the casing and chamber, then closing off the annular space between the well pipe and the casing, then disconnecting the chamber from the casing to allow introduction and removal of lengths of well pipe, again connecting the chamber to the casing, and completely opening the annulus surrounding the pipe within the casing and chamber to free the pipe from all external contact, and controlling the pressure 13 within the chamber to move the pipe; longitudinally of the casing and chamber.

2. in a system for controlling the movement of well pipe in a well bore having a casing therein, the steps of, first enclosing a length of well pipe in a pressure tight chamber connected to the well casing, then admitting to the chamber the pressure fluid present within the casing, and controlling the pressure within the chamber to move the pipe longitudinally of the casing and chamber, then closing off the annular space between the well pipe and the casing, and gripping the pipe to support the pipe in the well bore, then disconnecting the chamber from the casing to allow introduction and removal of lengths of well pipe, again connecting the chamber to the casing, and completely opening the annulus surrounding the pipe within the casing and chamber to free the pipe from all external contact, and controlling the pressure Within the chamber to move the pipe. longitudinally of the casing and chamber.

3. In a system for controlling the movement of well pipe in a well bore. having a, casing therein, the steps of, first enclosing a length of: well pipe in a pressure tight chamber connected to the well casing, then admitting to the chamber the. pressure fluid present within the casing, and controlling the pressure within the chamber to move the pipe longitudinally of the casing and chamber, rotating the well pipev while allowing the pipe to move longitudinally of the casing, then closing oil the annular space between the well pipe, and the casing, then disconnecting the chamber from the casing, to. allow introduction and removalof lengths of well pipe, again connecting the chamber to the casing, and completely opening the annulus surrounding the pipe within, the casing and chamber to free the pipe from all external contact, and controlling the pressure Within the chamber to move the pipe longitudinally ofthe casing and chamber.

4. In a system for controlling the movement of well pipe in a well bore having a casing therein, the steps of, first enclosing a length of well pipe in a pressure, tight chamber connected to the well casing, then admitting to the chamber the pressure fluid present within. the casing, and. controlling the pressure within. the chamber to move the pipe longitudinally of the casing and chamber, and passing fluid under pressure through the bore of the well pipe, then closing OK the annular space between the well pipe and the casing, then disconnecting the chamber from the casing to allow introduction and removal of lengths of well pipe, again connecting the chamber to the casing, and completely opening the annulus surrounding the pipe within the casing and chamber to free the pipe from all external contact, and controlling the pressure within the chamber to move the pipe longitudinally of the casing and chamber.

5. In a system for controlling the movement of well pipe in a well bore having a casing therein, the steps of, first enclosing a length of well pipe in a pressure tight chamber connected to the well casing, then admitting to the chamber the pressure fluid present within the easing, and controlling the pressure within the chamber to move the pipe longitudinally of the casing and chamber, rotating the well pipe while allowing the pipe to move longitudinally of the casing, and passing fluid under pressure through the bore of the well pipe, then closing off the annular space between the well pipe and the casing, and gripping the pipe to anchor the pipe in the well bore, then disconnecting the chamber from the casing to allow introduction and removal of lengths of well pipe, again connecting the chamber to the casing, and completely opening the annulus surrounding the pipe within the casing and chamber to free the pipe from all external contact, and controlling the pressure Within the chamber to move the pipe longitudinally of the casing and chamber.

6. A structure for controlling the movement of well pipes in a well bore including, a casing in the well bore, a cylinder connected in axial alinement with the casing in pressure tight relation, the interior of the casing and the cylinder being in direct communication and forming a continuous chamber of larger diameter than the well pipe whereby the well pipe may be received therein free of any external contact and pass freely through the interiors of said casing and cylinder, a piston in the cylinder, releasable connecting means disposed withinsaid cylinder for connecting the upper end of the well pipe thereto, and means for applying a pressure fluid within the cylinder to move the piston and well pipe longitudinally of the casing in a downward direction.

7. A structure for controlling the movement of. well pipe in a well bore as set forth in claim 6, and. a suspending means slidably connected to the upper end of the structure and separate from said piston for supporting the same.

8. A structure for controlling the movement of well pipe in a well bore including, a casing in the wellbore, a cylinder connected in axial alinement with the casing in pressure tight relation, the interiors of the casing and cylinder being in direct communication and forming a continuous chamber of larger diameter than the well pipe whereby the well pipe may be received therein free of any external contact and pass-freely through the interiors of said casing and cylinder, a piston in the cylinder, releasable connecting means disposed within said cylinder for connecting the upper endof the well pipe thereto, and means for applying a pressure fluid within the cylinder to move the piston and well pipe longitudinally of the casing in a downwardv direction, the connection between the cylinder and the casing being readily releasable.

9. A structure for controlling the movement of Well pipe in a well bore including, a casing in. the well bore, a cylinder connected in axial alinement with the casing in pressure tight relation, the interiors of the casing and cylinder being in direct communication and forming a continuous chamber of larger diameter than the Well pipe whereby the well pipe may be received therein free of any external contacts and pass freely through interiors of said casing and cylinder, a piston in the cylinder movable longitudinally relative to the cylinder, a releasable threaded connection between the piston and. the upper end of the well pipe, and means for applying a pressure fluid withinv the cylinder to move the. piston and well. pipe longitudinally of the casing.

10. A structure for controlling the movement of Well pipe in a well bore as set forth in claim 9, and a suspending means connected to the piston and extending upwardly above the cylinder.

11. The device as set forth in claim 9, including means to control the movement of the cylinder relative to the well pipe, comprising an auxiliary piston mounted in said cylinder.

12. A structure for controlling the movement of well pipe in a well bore including, a conductor in the well bore extending upwardly therefrom, a cylinder disposed above the conductor and connected thereto in axial alinement and pressure tight relation, the interiors of the conductor and cylinder being in direct communication and forming a continuous chamber of larger diameter than the well pipe whereby the well pipe may be received therein free of any external contact and pass freely through the interiors of said conductor and cylinder, pipe engaging elements carried by the conductor for gripping the well pipe, sealing elements carried by the conductor for sealing off the annulus between the conductor and the pipe, means for actuating the engaging elements and means for actuating the sealing elements into engagement with the well pipe and also operable for retracting said elements completely from the interior of the conductor so as to leave the same free and unobstructed, a piston in the cylinder movable longitudinally relative to the cylinder, a releasable threaded connection between the piston and the upper end of the well pipe, and means for applying a pressure fluid within the cylinder to the piston to move the piston and well pipe longitudinally of the casing.

13. A structure for controlling the movement of well pipe in a well bore as set forth in claim 12 wherein the means for actuating the engaging elements and for actuating the sealing elements are hydraulic means.

14. A structure for controlling the movement of well pipe in a well bore including, a casing in the well bore, a pipe gripping unit positioned above the upper end of the casing and having a pressure tight housing connected to the casing, said housing having a vertical passage in alinement with the casing and communicating in pressure tight relation therewith, pipe engaging elements in said housing, means for actuating said elements to project them into the vertical passage of the housing and retract them completely from said passage, a second housing positioned above and connected with said pressure tight housing and in pressure tight communication therewith and with the casing, sealing means in said second housing for sealing off between the well pipe and the latter housing, means for actuating the sealing means and projecting them into the interior of the second housing and withdrawing them completely therefrom, a cylinder positioned above said two housings and connected thereto in pressure tight relation, said cylinder and second housing having vertical passages in alinement with the well bore, the interiors of the casing and cylinder and both housings being in direct communication and forming a continuous chamber of larger diameter than the well pipe whereby the well pipe may be received therein free of any external contact and pass freely through the interior of said casing and cylinder and both housings, a piston in the cylinder adapted to be connected to the upper end of the well pipe, and means for admitting fluid pressure into said cylinder for moving the piston and well pipe longitudinally in the casing.

15. A structure for controlling the movement of well pipe in a well bore including, a casing in the well bore, a cylinder connected in axial alinement with the casing in pressure tight relation, the interiors of the casing and cylinder being in direct communication and forming a continuous chamber of larger diameter than the well pipe whereby the well pipe may be received therein free of any external contacts and pass freely through interiors of said casing and cylinder, a dual piston member in the cylinder adapted to be connected to the upper end of the well pipe, and means for applying a pressure fluid within the cylinder to move the well pipe longitudinally of the casing.

16. The device as set forth in claim 15, including means to control the movement of the cylinder relative to the pipe, comprising an auxiliary piston mounted in said cylinder.

17. A structure for controlling the movement of well pipe in a well bore including, a casing in the well bore, a cylinder connected in axial alignment with the casing in pressure-tight relation, the interiors of the casing and the cylinder being in direct communication and forming a continuous chamber of larger diameter than the well pipe, whereby the well pipe may be received therein free of any external contacts and pass freely through the interiors of said casing and cylinder, a piston in the cylinder adapted to be connected to the upper end of the well pipe, means for applying a pressure fluid within the cylinder to move the piston and well pipe longitudinally of the casing, a tube extending from the piston through the upper end of the cylinder, means for connecting the upper end of the well pipe to the piston so as to have the bore of the pipe in communication with the bore of the tube, and means for introducing a fluid under pressure into the bore of the tube.

18. A structure for controlling the movement of well pipe in a well bore as set forth in claim 17, including means carried in the chamber below the cylinder for rotating the well pipe while allowing the same to move longitudinally of the well bore.

19. A structure for controlling the movement of well pipe in a well bore as set forth in claim 18, including means for closing off the well bore.

References Cited in the file of this patent UNITED STATES PATENTS Re. 19,498 Otis Mar. 12, 1935 1,895,132 Minor Jan. 24, 1933 1,910,890 Fortune May 23, 1933 1,983,854 Howard et a1. Dec. 11, 1934 2,148,327 Smith et al. Feb. 21, 1939 2,180,680 Hild Nov. 21, 1939 

